P1602: THE ASSESSMENT OF LYMPHOPENIA AS RISK FACTOR FOR UNFAVORABLE EVOLUTION OF PATIENTS WITH SEVERE FORM OF COVID 19
Authors: V. Popov, L. Iliescu, A. Grigorie, C. Pirvu, O. Constantin, A. Badea, M. D. Badoiu Niculae, A. Rus, A. Calen, H. Bumbea, B. Mastalier, M. Andreescu
Journal: HemaSphere (2022)

Background: Coronavirus 2019 (COVID-19), the new infectious respiratory disease caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection is frequently associated with lymphopenia. Many studies involved lymphopenia as prognostic factor for unfavourable evolution of COVID-19 patients. Aims: The main objective is to evaluate the impact of lymphopenia in survival analyses of patients with severe and critical form of COVID-19. The secondary objectives is to evaluate another predictor variables that influenced the survival rate of COVID-19 patients. Methods: The retrospective observational study enrolled 261 COVID-19 patients with critical forms of COVID-19, who were admitted in Intensive Care Unit (ICU) between March2020-Sptember 2021. All patients have inform consent signed and RT-PCR test positive for SARS-Cov2. We consider lymphopenia, lymphocytes count bellow 1.0 x 1000/uL, the patient group was splitted by this factor in 2 groups. The analyses was done using clinical and lab data in order to identify parameter that could influence the evolution of COVID-19 in ICU-patients. Results: The COVID-19 patients group with lymphopenia (group1) have median age greater than COVID-19 patients without limphopenia (group2): 65 (min 26, max 89) vs. 54.5 (min 17, max 94), p=0.00002. Lymphopenia analysed as predictive factor of COVID-19 patients admitted in ICU is not important for survival analyses when was analysed alone. Patients with age < 65 years old and lymphopenia, with obesity (IMC>30) and oncological diseases have severe evolution, these patients developed severe pneumonia (more than 30-40% of pulmonary field evaluated CT scan); Wald 9.34, p=0.002; 0 p<0.0001. The inflammation assessment using feritina, CRP and Fibrinogen results was more severe in patient with lymphopenia: feritina- group 1-1031 (576,25-1749.25) vs group 2- 344.5 (134.25-848.75) uFEU, p< 0.0001; CRP group 1- 86.02 (40.04-159.2) mg/dl vs. group 2-12.18 (2.17-57.06) mg/dl, p<0.0001; fibrinogen group 1-554 (408-712) mg/dl vs group 2-396 (335-541) mg/dl, p<0.0001. These results could be explained by higher median time of viral clearance that is higher in patients with lymphopenia: group 1- 17 days (13.25-29) vs. group 2- 16 (9-25), p=0.03. The thrombotic complications are more frequent in severe form of COVID-19 patients who associated lymphopenia, group 1-28.22% vs group 2- 13.12%, Chi-squared 10.03, p=0.001, thrombosis was an important covariate in Cox proportional hazard regression, Wald 6.72, p=0.01 . In COVID 19 patients group 1 D Dimers level is higher than second group, 1.71 (0.80-4.36) vs. 0.64 (0.36-1.68), p<0.0001, the scoring system for disseminated intravascular coagulation (DIC) being higher in the first group; interquartile range 2-3 in group 1 vs 0-2 in group 2, p<0.0001. Summary/Conclusion: The inflammation and thrombotic complications are more frequent in COVID-19 patients with lymphopenia. Persistent viral clearance in patients with lymphopenia is likely to contribute to the clinical severity and adverse outcome of COVID-19. The results obtained require evaluation in a larger group of patients